By JEFF GERTH and TIM WEINER

Published: September 29, 1997

WASHINGTON, Sept. 28—
Since the 1980's, food imports to the United States have doubled. But Federal inspections of those imports by the Food and Drug Administration have dropped to less than half what they were five years ago.

Now, public-health scientists say they are seeing more and more outbreaks of disease linked to imported food, particularly fresh fruit and vegetables.

These are known to have sickened thousands of Americans, and those reported cases are a small fraction of the actual number of people made ill, according to scientists at the Centers for Disease Control and Prevention in Atlanta.

The scientists' list of outbreaks in the 1990's implicates imported foods -- including raspberries from Guatemala and carrots from Peru; strawberries, scallions and cantaloupes from Mexico; coconut milk from Thailand; canned mushrooms from China; an Israeli snack food, and a multinational batch of alfalfa sprouts -- in a variety of infectious diseases.

The increase in imports has strained the nation's food-safety system, said Dr. David A. Kessler, the Food and Drug Administration commissioner from 1990 through February 1997. ''We built a system back 100 years ago that served us very well for a world within our borders,'' he said in an interview. ''We didn't build a system for the global marketplace.''

Most of the food imported to the United States is wholesome. Consumers, knowing that fresh produce is good for their health, can now buy reasonably priced fruits and vegetables imported from around the world, regardless of the season, and without ill effect.

But the illnesses that have been imported along with some of the produce are an unintended byproduct of the boom in international trade -- a boom long advocated by the Reagan, Bush and Clinton Administrations as crucial to economic growth.

There is ''a tension between the two goals of safety and trade,'' said Mickey Kantor, President Clinton's first trade representative, who helped push global trade to the top of Mr. Clinton's agenda. ''You want to open markets but not lower standards. And that's easy to say, but very, very difficult to carry out.''

Scientists are recognizing that ''free trade may present problems that are associated with food poisoning,'' said Dr. Marguerite A. Neill, an infectious disease specialist and a member of a Federal advisory panel drafting new food-safety standards. These problems cut both ways: radish sprouts from Oregon seeds sickened people in Japan in March, and South Korea said it detected E. coli bacteria in a shipment of frozen United States beef last week.

The problems imports may pose for American consumers include polluted water used to grow food in third-world nations, faulty safety systems in countries where the foods are produced, and a lack of natural immunity to exotic microbes rarely seen in this country. ''Certain viruses, bacteria and parasites may be posing a unique problem in the U.S. because we haven't tended to be exposed to them,'' Dr. Neill said.

Dr. Yasmine Motarjemi, a World Health Organization food-safety scientist, said the organization also believed that global trade ''brings new pathogens into countries which are not immune.''

Those problems were foreseeable -- and foreseen.

In 1994, a Centers for Disease Control report said, ''As trade and economic developments like Nafta take place, the globalization of food supplies is likely to have an increasing impact on food-borne illnesses.''

In 1993, the Food and Drug Administration, in a memorandum citing ''enormous inefficiencies in the current food-protection system'' and the ''ever-increasing challenges'' posed by rapidly growing imports, asked the Clinton Administration for legislation giving it power to bar all food -- including fruits, grains, vegetables and fish -- imported from any country with an inferior food-safety system.

The Department of Agriculture has such authority over imported meat and poultry. But the F.D.A. never acquired that power though legislation or executive order.

Dr. Kessler said in an interview that he had told the Bush and Clinton Administrations that the safety system for imported food was inadequate and outdated.

''How is it physically possible to insure the safety of imported food?'' he said. ''You don't have police power throughout the world. Inspecting at the border has a limited value. You're left with real risks.''

Now these risks figure in the political debate about free trade.

The Clinton Administration wants the power to sign new free-trade pacts without Congress's changing the language of those agreements. Opponents of this ''fast track'' authority raise the food-safety flag. Some food growers say that the risks from imports are insignificant, and that the C.D.C. exaggerates them.

The C.D.C. says diseases borne by domestic and foreign foods kill thousands of Americans and sicken millions, perhaps tens of millions, every year -- mostly the very young, the very old and the very ill. Its scientists say almost none of those cases are ever traced back to their cause. As a result, they say, they lack the data to show how many people get sick from imported food, and whether that food is safer or less safe than domestic food.

Both sides in the fast track debate use the Centers for Disease Control's data to make their cases -- and both sides mischaracterize what the data show, according to the scientists.